61 research outputs found
Hydrogen H line polarization in solar flares. Theoretical investigation of atomic polarization by proton beams considering self-consistent NLTE polarized radiative transfer
Context. We present a theoretical review of the effect of impact polarization
of a hydrogen H line due to an expected proton beam bombardment in
solar flares. Aims. Several observations indicate the presence of the linear
polarization of the hydrogen H line observed near the solar limb above
5% and preferentially in the radial direction. We theoretically review the
problem of deceleration of the beam originating in the coronal reconnection
site due to its interaction with the chromospheric plasma, and describe the
formalism of the density matrix used in our description of the atomic processes
and the treatment of collisional rates. Methods. We solve the self-consistent
NLTE radiation transfer problem for the particular semiempirical chromosphere
models for both intensity and linear polarization components of the radiation
field. Results. In contrast to recent calculations, our results show that the
energy distribution of the proton beam at H formation levels and
depolarizing collisions by background electrons and protons cause a significant
reduction of the effect below 0.1%. The radiation transfer solution shows that
tangential resonance-scattering polarization dominates over the impact
polarization effect in all considered models. Conclusions. In the models
studied, proton beams are unlikely to be a satisfying explanation for the
observed linear polarization of the H line.Comment: 11 pages, 11 figures, accepted for publication in A&
Photometric properties of resolved and unresolved magnetic elements
We investigate the photometric signature of magnetic flux tubes in the solar
photosphere. We developed two dimensional, static numerical models of isolated
and clustered magnetic flux tubes. We investigated the emergent intensity
profiles at different lines-of-sight for various spatial resolutions and
opacity models. We found that both geometric and photometric properties of
bright magnetic features are determined not only by the physical properties of
the tube and its surroundings, but also by the particularities of the
observations, including the line/continuum formation height, the spatial
resolution and the image analyses techniques applied. We show that some
observational results presented in the literature can be interpreted by
considering bright magnetic features to be clusters of smaller elements, rather
than a monolithic flux tube.Comment: 12 page
Fast and simple procedure for fractionation of zinc in soil using an ultrasound probe and FAAS detection. Validation of the analytical method and evaluation of the uncertainty budget
Modeling High-Intensity Pulsed Electric Field Inactivation of a Lipase from Pseudomonas fluorescens
Reduction of Protease Activity in Simulated Milk Ultrafiltrate by Continuous Flow High Intensity Pulsed Electric Field Treatments
Determination of total lead and lead species according to their lability in coastal seawater by Chelex-100 titration and electrothermal-atomic absorption spectrometry
Embedding knowledge in 3d data frameworks in cultural heritage
At present, where 3D modeling and visualisation in cultural heritage are concerned, an object's documentation lacks its interconnected memory provided by multidisciplinary examination and linked data. As the layers of paint, wood, and brick recount a structure's physical properties, the intangible, such as the forms of worship through song, dance, burning incense, and oral traditions, contributes to the greater story of its cultural heritage import. Furthermore, as an object or structure evolves through time, external political, religious, or environmental forces can affect it as well. As tangible and intangible entities associated with the structure transform, its narrative becomes dynamic and difficult to easily record. The Initial Training Network for Digital Cultural Heritage (ITN-DCH), a Marie Curie Actions project under the EU 7th Framework Programme, seeks to challenge this complexity by developing a novel methodology capable of offering such a holistic framework. With the integration of digitisation, conservation, linked data, and retrieval systems for DCH, the nature of investigation and dissemination will be augmented significantly. Examples of utilisating and evaluating this framework will range from a UNESCOWorld Heritage site, the Byzantine church of Panagia Forviotissa Asinou in the Troodos Mountains of Cyprus, to various religious icons and a monument located at the Monastery of Saint Neophytos. The application of this effort to the Asinou church, representing the first case study of the ITN-DCH project, is used as a template example in order to assess the technical challenges involved in the creation of such a framework
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